Biological Characteristics of Soil MCQ's Q & A PDF

What is the primary role of earthworms in soil? A. To mix soil layers and improve drainage B. To reduce the soil\'s carbon footprint C. To release CO2 into the atmosphere D. To break down organic matter into simple nutrients ANSWER: A What is the ideal pH range for earthworms to thrive? A. pH...

What is the primary role of earthworms in soil? A. To mix soil layers and improve drainage B. To reduce the soil\'s carbon footprint C. To release CO2 into the atmosphere D. To break down organic matter into simple nutrients ANSWER: A What is the ideal pH range for earthworms to thrive? A. pH 7-9 B. pH 8-10 C. pH 6-8 D. pH 5-7 ANSWER: C What process converts CO2 into a carbohydrate during photosynthesis? A. Decomposition B. Respiration C. Consumption D. Photosynthesis ANSWER: D What is the primary form of carbon stored in soil? A. Carbohydrate B. Carbonate ion C. CO2 D. Organic Carbon ANSWER: D How can farmers reduce their carbon footprint? A. By increasing diesel usage B. By burning more straw C. By planting more trees and reducing tillage D. By harvesting more peat ANSWER: C What is the role of rhizobium bacteria in the nitrogen cycle? A. To convert nitrate to nitrogen gas B. To convert ammonium to nitrate C. To fix nitrogen into nitrate D. To denitrify nitrogen gas ANSWER: C What is the process by which nitrate is converted back to nitrogen gas? A. Nitrogen fixation B. Denitrification C. Nitrification D. Decomposition ANSWER: B What is the role of bacteria in the decomposition process? A. To convert nitrate to ammonium B. To fix nitrogen into nitrate C. To break down organic matter into simple nutrients D. To release CO2 into the atmosphere ANSWER: C What is the percentage of organic carbon in soil organic matter? A. 40% B. 60% C. 50% D. 58% ANSWER: D What is the formula to calculate Soil Organic Carbon (SOC)? A. SOC = SOM / 0.58 B. SOC = SOM x 0.5 C. SOC = SOM x 0.58 D. SOC = SOM / 2 ANSWER: C What is the term for the total amount of organic matter living in the soil? A. Soil organic matter B. Soil humus C. Soil biomass D. Soil nutrient ANSWER: C What type of relationship exists between mycorrhizal fungi and plants? A. Saprophytic B. Symbiotic C. Parasitic D. Mutualistic ANSWER: D What is the primary role of bacteria in the Nitrogen cycle? A. To enhance water holding capacity of the soil B. To convert organic matter into humus C. To convert nitrogen into usable forms D. To add nutrients to the soil in the form of faeces ANSWER: C What is the area around a plant root where the biological and chemical aspects of the soil are influenced by the root? A. Rhizosphere B. Soil biomass C. Soil humus D. Soil organic matter ANSWER: A What is the process of decomposing organic matter into humus? A. Decomposition B. Humification C. Mineralization D. Nutrification ANSWER: B What type of relationship exists between fungi and plants in the rhizosphere? A. Parasitic B. Symbiotic C. Mutualistic D. Saprophytic ANSWER: B What is the term for an organism that feeds off dead organic matter? A. Saprophyte B. Symbiont C. Mutualist D. Parasite ANSWER: A What is the benefit of mycorrhizal fungi to plants? A. Enhance water holding capacity B. Bind soil particles together C. Provide nutrients to the plant D. All of the above ANSWER: D What is the primary form of nitrogen stored in plants? A. Nitrogen gas B. Plant protein C. Ammonium D. Nitrate ANSWER: B What is the role of Nitrosomas bacteria in the nitrogen cycle? A. Nitrogen fixation B. Nitrification C. Decomposition D. Denitrification ANSWER: B What is the primary function of microorganisms in the rhizosphere? A. To break down complex organic compounds into simpler ones B. To decompose organic matter into humus C. To release nutrients from the soil for plant uptake D. To convert nitrogen into ammonia ANSWER: C What is the primary role of denitrifying bacteria in the nitrogen cycle? A. Nitrogen fixation B. Denitrification C. Decomposition D. Nitrification ANSWER: B What is the main benefit of mycorrhizal fungi to plants in terms of water relations? A. Improved water use efficiency B. Reduced water loss through transpiration C. Increased water uptake through roots D. Enhanced water holding capacity of the soil ANSWER: D What is the term for the process of converting ammonia to nitrate in the soil? A. Decomposition B. Nitrogen fixation C. Nitrification D. Denitrification ANSWER: C What is the term for the process of converting nitrogen gas to nitrate in the soil? A. Nitrification B. Decomposition C. Nitrogen fixation D. Denitrification ANSWER: C What is the term for an organism that lives on or in a living host, usually causing harm? A. Saprophyte B. Symbiont C. Parasite D. Mutualist ANSWER: C